Whooping cough is an infection of the lining of the airways. It mainly affects the windpipe and the two airways that branch off from it to the lungs.
Daybreak's Health Editor Dr Hilary Jones explains;
More top news
A shock to the system
We found a tableau of desperation; vast crowds of people pushing and shoving their way forward, away from the continuing bombardment.
Cambridge Analytica played a key role in mapping behaviour of voters in the US election and was used during the EU referendum campaign.